• Food Science and Preservation
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• v.23 no.1
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• pp.97-103
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• 2016

The antioxidant and digestive enzyme inhibitory effects of Eisenia bicyclis extracted by various extraction methods (RE, reflux extraction; SE, ultrasonification extraction; AE, autoclave extraction; LE, low-temperature high-pressure extraction) were investigated. The extraction yield (55.21%) and the laminarin (39.03%), fucoidan (24.75%), total polyphenol (115.68 mg GAE/g) and flavonoid (36.67 mg RHE/g) contents of AE were higher than those in other methods. The DPPH radical (86.60%, 500 mg%), ABTS radical (58.56%, 25 mg%), nitrite (86.38%, 100 mg%) scavenging activities of the Eisenia bicyclis extracted by AE were higher than those of Eisenia bicyclis extracted by other methods. The ABTS radical and nitrite scavenging activities were above 98% in all tested Eisenia bicyclis extracts and these activities were dependent on its concentration. The inhibitory effects of AE against amylase (50 mg%) and ${\alpha}$-glucosidase (5 mg%) were 64.76% and 86.71%, respectively. The AE showed the best inhibitory effect of Eisenia bicyclis extracts (50 mg%) against trypsin (24.37%) and ${\alpha}$-chymotrypsin (49.05%), respectively. These results suggest that Eisenia bicyclis extracted by AE can be used as a bioactive and functional material in the food industry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.67-67
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• 2009

Due to the scaling down of the dielectrics thickness, the leakage currents arising from electron tunneling through the dielectrics has become the major technical barrier. Thus, much works has focused on the development of high k dielectrics in both cases of memories and CMOS fields. Among the high-k materials, $Al_2O_3$ considered as good candidate has been attracting much attentions, which own some good properties as high dielectric constant k value (~9), a high bandgap (~2eV) and elevated crystallization temperature, etc. Due to the easy control of ion energy and flux, low ownership and simple structure of the inductively coupled plasma (ICP), we chose it for high-density plasma in our study. And the $BCl_3$ was included in the gas due to the effective extraction of oxygen in the form of BClxOy compound. In this study, the etch characteristic of ALD deposited $Al_2O_3$ thin film was investigated in $BCl_3/N_2$ plasma. The experiment were performed by comparing etch rates and selectivity of $Al_2O_3$ over $SiO_2$ as functions of the input plasma parameters such as gas mixing ratio, DC-bias voltage and RF power and process pressure. The maximum etch rate was obtained under 15 mTorr process perssure, 700 W RF power, $BCl_3$(6 sccm)/$N_2$(14 sccm) plasma, and the highest etch selectivity was 1.9. We used the x-ray photoelectron spectroscopy (XPS) to investigate the chemical reactions on the etched surface. The Auger electron spectroscopy (AES) was used for elemental analysis of etched surface.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1300-1307
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• 1999

Supercritical fluid extraction was applied to recycling triglyceride from used shortening. Used shortening and its fractions were analyzed with high performance size exclusion chromatography for their composition in triglycerides, polymer and low molecular weight compounds. Conjugated diene value and color of the fractions were also measured with a UV spectrophotometer and a colorimeter, respectively. Pressure and temperature ranges employed were $15{\sim}30$ MPa and $40{\sim}60^{\circ}C$, respectively. Concentration of fat in supercritical (SC) $CO_2$ ranged from $0.3\;X\;10^{-3}{\sim}7.4\;X10^{-3}(g\;fat/g\;CO_2)$. An exponential relation between concentration of fat in SC $CO_2$ and density was observed. Color of the extracts was light yellow which was very close to that of the fresh shortening. Low molecular weight compounds were preferentially concentrated in the initial fraction, while polymer was extracted in the final fraction. Conjugated diene value of the initial fractions was clearly lower than that of feed. It increased sharply as the polymer content in the fraction became significantly large.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.169-169
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• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.

• Korean Journal of Food Science and Technology
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• v.14 no.3
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• pp.244-249
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• 1982

In order to reduce malic acid in low-alcohol content appel wine $(6{\sim}9%)$ malate-decomposing yeast, Schzosaccharomyces japonicus var. japonicus St-3 was used. Fallen apples before the harvesting season were collected and extraction was made. The apple extract was fortified with sucrose to make final sugar concentration of 18% in case of 9% base wine. High acid content in the primarily fermented apple wine could be reduced by following with malo-alcoholic fermentation using Schizosaccharomyces japonicus var. japonicus St-3 in second half of alcoholic fermentation using Saccharomyces sp. R-11. Secondary fermentation was proceeded at low temperature $(7{\sim}8^{\circ}C)$ for 130 days using Saccharomyces sp. R-11. Prior to the secondary fermentation, two percent of sugar was added to the base wine in order to produce carbon dioxide gas. And each five percent of specially prepared malt extract and hop extract were added to the base wine in order to increase foam stability. Better shelf-life was observed by keeping high carbon dioxide pressure$(2.3{\sim}2.5kg/cm^2)$ in the bottle. It was assured that the better low-alcohol content apple wine could be brewed by the method which we used above.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.68-75
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• 2013

The physiological properties of water extracts from Jerusalem artichoke (Helianthus tuberosus L.) leaves (JAL) with different extraction processes (stirrer extraction, SE; reflux extraction, RE; autoclave extraction, AE; low temperature high pressure extraction, LTPE) were investigated. The freeze-dried powder yields of SE, RE, AE, and LTPE were 22.33%, 29.88%, 31.65, and 15.74%, respectively. AE showed the highest value of extract yield. The $a^*$ and $b^*$ values were higher in AE compared to other extracts. Total polyphenolics and flavonoids contents in AE was significantly higher than in other extracts. The amount of proanthocyanidin related substances were highest in LTPE (29.36 mg/g), followed by RE (21.57 mg/g), SE (20.35 mg/g), and AE (13.02 mg/g). The electron donating abilities of SE, RE, AE, and LTPE at a concentration of $500{\mu}g/mL$ (w/v) were 76.16%, 39.55%, 25.50%, and 12.59%, respectively. Reducing power for the four different processes was 1.79, 1.60, 1.51, and 1.17, respectively. Additionally the same tendency was observed with electron donating ability and reducing power for ABTS radical and nitrite scavenging abilities. AE and LTPE showed relatively high antioxidant activities. Alpha-glucosidase, xanthine oxidase, and angiotensin I-converting enzyme inhibitory activities of LTPE at a concentration of $500{\mu}g/mL$ (w/v) were somewhat higher than other extracts. Additionally, there was significantly higher or little lower inhibitory activity compared to the control group. In conclusion, we provided experimental evidence that extracts of JAL have potential as functional materials, and component analysis of JAL could be used as new cosmeceuticals. Also, LTPE is the superior method for the enhancement of biological activity.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.39-42
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• 1999

Perfluoropolymers represent the ultimate resistance to hostile chemical environments and high service temperature, attributed to the presence of fluorine in the polymer backbone, i.e. to the high bond energy of C-F and C-C bonds of fluorocarbons. Copolymers of Tetrafluoroethylene (TEE) and 2, 2, 4Trifluoro-5Trifluorometoxy- 1, 3Dioxole (TTD), commercially known as HYFLON AD, are amorphous perfluoropolymers with glass transition temperature (Tg)higher than room temperature, showing a thermal decomposition temperature exceeding 40$0^{\circ}C$. These polymer systems are highly soluble in fluorinated solvents, with low solution viscosities. This property allows the preparation of self-supported and composite membranes with desired membrane thickness. Symmetric and asymmetric perfluoropolymer membranes, made with HYFLON AD, have been prepared and evaluated. Porous and not porous symmetric membranes have been obtained by solvent evaporation with various processing conditions. Asymmetric membranes have been prepared by th wet phase inversion method. Measure of contact angle to distilled water have been carried out. Figure 1 compares experimental results with those of other commercial membranes. Contact angles of about 120$^{\circ}$for our amorphous perfluoropolymer membranes demonstrate that they posses a high hydrophobic character. Measure of contact angles to hexandecane have been also carried out to evaluate the organophobic character. Rsults are reported in Figure 2. The observed strong organophobicity leads to excellent fouling resistance and inertness. Porous membranes with pore size between 30 and 80 nanometers have shown no permeation to water at pressures as high as 10 bars. However high permeation to gases, such as O2, N2 and CO2, and no selectivities were observed. Considering the porous structure of the membrane, this behavior was expected. In consideration of the above properties, possible useful uses in th field of gas- liquid separations are envisaged for these membranes. A particularly promising application is in the field of membrane contactors, equipments in which membranes are used to improve mass transfer coefficients in respect to traditional extraction and absorption processes. Gas permeation properties have been evaluated for asymmetric membranes and composite symmetric ones. Experimental permselectivity values, obtained at different pressure differences, to various single gases are reported in Tab. 1, 2 and 3. Experimental data have been compared with literature data obtained with membranes made with different amorphous perfluoropolymer systems, such as copolymers of Perfluoro2, 2dimethyl dioxole (PDD) and Tetrafluorethylene, commercialized by the Du Pont Company with the trade name of Teflon AF. An interesting linear relationship between permeability and the glass transition temperature of the polymer constituting the membrane has been observed. Results are descussed in terms of polymer chain structure, which affects the presence of voids at molecular scale and their size distribution. Molecular Dyanmics studies are in progress in order to support the understanding of these results. A modified Theodoru- Suter method provided by the Amorphous Cell module of InsightII/Discover was used to determine the chain packing. A completely amorphous polymer box of about 3.5 nm was considered. Last but not least the use of amorphous perfluoropolymer membranes appears to be ideal when separation processes have to be performed in hostile environments, i.e. high temperatures and aggressive non-aqueous media, such as chemicals and solvents. In these cases Hyflon AD membranes can exploit the outstanding resistance of perfluoropolymers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.389-396
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• 2014

The physiological properties of 70% ethanol extracts from Portulaca oleracea with different extraction methods (reflux extraction, RE; autoclave extraction, AE; low temperature high pressure extraction, LTPE) were investigated. The freeze-dried powder yields of RE, AE, and LTPE were 33.78%, 30.80%, and 11.05%, respectively. The color values of L and b were higher in LTPE, and the chroma values were higher in AE and LTPE compared to RE. The total polyphenolics and proanthocyanidin contents in LTPE were significantly higher than in other extracts. The amount of substances related to flavonoids contents was highest in RE (4.30 mg/g), followed by AE (4.06 mg/g), and LTPE (4.00 mg/g). DPPH radical scavenging ability with a concentration of 500 mg% (w/v) were in the following order; LTPE (88.87%)> RE (83.84%)> AE (80.67%). Further, the reducing power, ABTS radical scavenging ability, and nitrite scavenging activity was observed in the same tendency as seen with the DPPH radical scavenging ability. However, the ferrous ion chelating activity of RE (85.45%) and AE (83.88%) was significantly higher than that of LTPE (75.60%). ${\alpha}$-Glucosidase inhibitory activities of RE and LTPE with a concentration of 100 mg% were significantly higher than AE. Xanthine oxidase, and acetylcholinesterase inhibitory activities of LTPE were higher than the other extracts. These results suggest that the extracts from Portulaca oleracea have the potential to act as functional materials, and components of Portulaca oleracea could be effective in the prevention of Alzheimer's disease, and may be used to develop various functional food products.

• Journal of the Korean Wood Science and Technology
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• v.7 no.2
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• pp.3-30
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• 1979

Larch ($\underline{Larix}$ $\underline{leptolepis}$ GORDON), one of the major afforestation species in Korea in view of its growing stock and rate of growth, is not favored as a raw material for pulp due to its low yield of pulp and difficulties with bleaching arising from the high content of extractives in wood, and the high heartwood ratio and the active phenolics, respectively. The purpose of this study is to investigate the characteristics of firstly pulping with various additives of cellulose protector for the yield of pulp, and secondly bleaching with oxygen for chlotination-alkali extraction of five stage-sequence to reduce chlorine compounds in bleaching effluents. The kraft cooking liquor for five age groups of larchwood was 18 percent active alkali with 25 percent sulfidity and 5 : 1 liquor-to-wood ratio, and each soda liquor for sap-and heart-wood of the 15-year-old larchwood was 18 percent alkali having one of the following cellulose protectors as the additive; magnesium sulfate ($MgSO_4$, 2.5%), zinc sulfate ($ZnSO_4$, 2.5%), aluminium sulfate ($Al_2(SO_4)_3$, 2.5%), potasium iodide (KI, 2.5%), hydroquinone (HQ, 2.5%), anthraquinone (AQ, 0.1%) and ethylene diamine (EDA, 2.5%). Then each anthraquinone-soda liquor for the determination of suitable cooking condition was the active alkali level of 15, 17 and 19 percent with 1.0, 0.5 and 0.1 percent anthraquinone, respectively. The cooking procedure for the pulps was scheduled to heat to 170$^{\circ}C$ in 90 minutes and to cook 90 minutes at the maximum temperature. The anthraquinone-soda pulps from both heartwood and sapwood of 15-year-old larchwood prepared with 0.5 percent anthraquinone and 18 percent active alkali were bleached in a four-stage sequency of OCED. (O: oxygen bleaching, D: chlorine dioxide bleaching and E: alkali extraction). In the first stage oxygen in atmospheric pressure was applied to a 30 percent consistency of pulp with 0.1 percent magnesium oxide (MgO) and 3, 6, and 9 percent sodium hydroxide on oven dry base, and the bleached results were compared pulps bleached under the conventional CEDED (C: chlorination). The results in the study were summarized as follows: 1. The screened yield of larch kraft pulp did not differ from particular ages to age group, but heartwood ratio, basic density, fiber length and water-extractives contents of wood and the tear factor of the pulp increased with increasing the tree age. The total yield of the pulp decreased. 2. The yield of soda pulp with various chemicals for cellulose protection of the 15-year-old larchwood increased slightly more than that of pure soda pulp and was slightly lower than that of kraft pulp. The influence of cellulose protectors was similar to the yield of pulps from both sapwood and heartwood. The effective protectors among seven additives were KI, $MgSO_4$ and AQ, for which the yields of screened pulp was as high as that of kraft pulp. Considering the additive level of protector, the AQ was the most effective in improving the yield and the quality of pulp. 3. When the amount of AQ increased in soda cooking, the yield and the quality of the pulp increased but rejects in total yield increased with decreasing the amount of active alkali from 19 to 15 percent. The best proportion of the AQ seemed to be 0.5 percent at 17 percent active alkali in anthraquinone-soda pulping. 4. On the bleaching of the AQ-soda pulp at 30 percent consistency with oxygen of atomospheric pressure in the first stage of the ODED sequence, the more caustic soda added, the brighter bleached pulp was obtained, but more lignin-selective bleaching reagent in proportion to the oxygen was necessary to maintain the increased yield with the addition of anthraquinone. 5. In conclusion, the suitable pulping condition for larchwood to improve the yield and quality of the chemical pulp to the level for kraft pulp from conventional process seemed to be. A) the selection of young larchwood to prevent decreasing in yield and quality due to the accumulation extractives in old wood, B) the application of 0.5 percent anthraquinone to the conventional soda cooking of 18 percent active alkali, and followed, C) the bleaching of oxygen in atmospheric pressure on high consistency (30%) with 0.1 percent magnesium oxide in the first stage of the ODED sequence to reduce the content of chlorine compounds in effluent.